The present invention relates, in general, to semiconductors, and more particularly, to a novel semiconductor device.
Modulation doped field effect transistors (MODFETs) also known as high electron mobility transistors (HEMTs), are well known in the semiconductor industry. MODFETs and HEMTs have high gain and high frequency performance and generally are used in applications requiring these characteristics. Such transistors generally have the source, gate, and drain in close proximity to one another in order to maintain the high frequency and high performance characteristics. One problem with the prior transistor structures is the breakdown voltage and current handling capability of the devices. Because of the close proximity between the source, gate, and drain, the breakdown voltage typically has a maximum value that is less than approximately 10 volts. Also, the current density achievable with the prior devices is low because current flow is limited to one channel per gate. Consequently, such transistors generally are not suitable for applications requiring high power handling capabilities.
Accordingly, it is desirable to have a high performance power device that has a high breakdown voltage, and a high current density.